In the bakery industry, frozen dough is commonly used for the production and baking of raw dough in on-site bakeries or retail outlets.
The method uses dough pieces which are quickly snap frozen into their frozen shape at a production facility. The frozen dough pieces are transported from the production facility to the retail outlet where they are stored in freezers. When required the frozen dough pieces are thawed. As the dough is already in the shape of the finished product, the thawed dough pieces are placed on baking utensils such as trays for proofing. Once the dough product has doubled in bulk, they are baked to provide the finished product.
This process has a number of advantages and disadvantages. The advantage of this method is that a large variety of low volume product can be produced daily. As the dough is already shaped, a low level of skill is required on the part of the operator and compared with other bakery processes, a smaller floor area is required which is easier to manage and keep clean. As such product is generally sold at smaller retail outlets, there is a synergy with other frozen product which is brought in and baked, such as pastry, pies and cake.
The disadvantages of this method is that the frozen dough pieces are in the shape of the finished product and therefore often bulky to transport. Furthermore the frozen dough pieces must be transported in refrigerated transports increasing the overall costs of the product.
With frozen dough, it is essential that the thawing process is accurately controlled and completed if a consistent quality product is to be produced. In particular, the accumulation of excessive moisture in the dough pieces may lead to difficulties in handling and/or an inferior quality product. The problem is exacerbated when the thawing environment is subject to atmospheric variations.
If a number of different products is required then a number of different types of frozen dough need to be thawed. The shape, thickness, density and type of dough will vary depending on the type of product being produced requiring different timing and conditions for the thawing of each product. Thus if numerous products are to be produced, scheduling of the thawing process and the number of thawers becomes a limiting constraint. Furthermore in order for the thawed dough pieces to prove and rise, it is essential that the yeast culture is protected from the freezing process. This generally requires addition of preservative ingredients to the dough thereby increasing the costs of each frozen item. A further disadvantage is that the frozen item needs to be removed by hand from individual boxes in the freezer to be placed in receptacles in the thawer which is often a time consuming and uncomfortable process for the operator.
The applicant has recently developed an improved baking process. This process is described in applicant's PCT application (PCT/AU2006/000691), the contents of which are incorporated herein by reference. This process provides a thawing processing which is applied to frozen dough pieces in a substantially planar shape in which each of the dough pieces is preferably of the same or similar size and thickness. During the thawing process of the substantially planar frozen dough pieces, warm air is directed onto the centre of the frozen dough piece for a predetermined period of time, to dry and thaw the still frozen surface of the dough.
A limitation of this process is that changes in the thawing characteristics of the warm air stream result in a variable quality product. Therefore, in order to fully utilise the invention described in PCT/AU2006/000691, it is desirable to improve the stated process. Furthermore, by providing an improved thawing process and thawing apparatus, the principles of controlled thawing can be extended beyond thawing substantially planar shaped dough pieces.
Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment, or any form of suggestion, that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art.